Revenue for the world's IT security market is expected to near $13 billion in 2004, with Cisco Systems Inc., Symantec Corp. and VeriSign Inc. leading the market, a research firm said Monday.

The projected $12.9 billion market consists of three components, threat mitigation, command and control and managed security services, The Yankee Group said.

Threat mitigation covers layered defenses against worms and viruses, denial of services attacks, intrusions and buffer overflows. The technologies include perimeter firewalls, network integrity systems, application gateways and system-integrity software, which collectively is expected to represent $5.4 billion, or 42 percent of the market, Yankee said.

Command and control, which includes identity management, security event management, vulnerability assessments and patching, and intrusion detection audits, account for 40 percent of the market, or $5.2 billion.

Managed security services, the use of external expertise in operating and improving security processes, accounts for the remaining $2.3 billion, or 18 percent, of the market.

Yankee analyst Phebe Waterfield said network equipment maker Cisco, security software maker Symantec and VeriSign, known for digital identities for secure communications on the web, are the market leaders.

Challengers, however, included publicly traded companies Microsoft Corp. and America Online Inc., a division of Time Warner Inc.; as well as a host of private companies, including Arbor Networks, Sana Security, Determina, Skybox Security, Imperva, Teros, Qualys, IronPort, NetSec, Perfigo, TruSecure and Sourcefire.

In its market prediction, Yankee expects more security features to become commoditized and move to the network to improve scalability of deployment and lower the cost of ownership. The trend has started with anti-virus software, and is expected to continue with basic firewall features, which are finding their way into routers and switches.

"The compelling attraction of intrusion prevention techniques in the network and on host systems threatens market dominance of legacy anti-virus and intrusion detection vendors," Waterfield said.